16.1
16.2
16.2 Continued
16.3
Mystery
100
Placing the north pole of a magnet near the south pole of another magnet results in: a. an attractive force between the magnets. b. a repulsive force between the magnets. c. an electric force between the magnets. d. no force between the magnets.
What is a. an attractive force between the magnets.
100
If you reverse the direction of current flow in an electromagnet: a. the north and south poles are reversed. b. the magnet is neutralized. c. the strength of the magnetic field increases. d. a short circuit occurs.
What is a. the north and south poles are reversed.
100
The source of a material’s magnetism is the: a. charge of its protons. b. mass of its neutrons. c. spin of its electrons. d. density of its nucleus.
What is c. spin of its electrons.
100
Earth’s magnetic north pole is: a. aligned with the north star. b. aligned with Earth's geographic north pole. c. under Antarctica, near Earth's geographic south pole. d. at the equator.
What is c. under Antarctica, near Earth's geographic south pole.
100
In which area of Figure 16-2A is the magnetic field strongest? a. A b. B c. C d. D
What is d. D
200
If a 12-inch long bar magnet is cut into two pieces, one inch from the north pole end of the magnet: a. the short piece of the magnet has a north pole on one end and no pole on the other. b. the long piece of the magnet has a south pole on both ends. c. the short piece has a north pole on both ends. d. both pieces have a north and a south pole on each end.
What is d. both pieces have a north and a south pole on each end.
200
Materials in which each atom has a tiny magnetic field, but the north and south poles of atoms within the material are randomly arranged so that the magnetic fields cancel out, are known as: a. nonmagnetic. b. paramagnetic c. diamagnetic. d. monomagnetic.
What is b. paramagnetic
200
Materials in which the magnetic fields of individual electrons in an atom cancel out so that each atom has zero net magnetic field are known as: a. ferromagnetic. b. paramagnetic. c. diamagnetic. d. monomagnetic.
What is c. diamagnetic.
200
The earliest records of magnetically aided navigation are found in the history of the: a. Japanese. b. Italians. c. Greeks. d. Chinese.
What is c. Greeks.
200
Electromagnets are generally more useful than permanent magnets for all of the following reasons EXCEPT: a. they are always magnetized. b. their polarity can be changed. c. their strength can be altered. d. the magnetism can be turned off.
What is a. they are always magnetized.
300
Which pair of objects in Figure 16-1A experiences a repulsive force? a. A and B b. A and C c. B and D d. B and C
What is b. A and C
300
Using the right hand rule, the magnetic poles of the device in Figure 16-3A are located: a. North at the “head” and South at the “point.” b. North at the “point” and South at the “head.” c. East at the “point” and West at the “head.” d. East at the “head” and West at the “point.”
What is a. North at the “head” and South at the “point.”
300
An example of a ferromagnetic material is a: a. ceramic mug. b. nail attracted to a bar magnet. c. penny. d. CD.
What is b. nail attracted to a bar magnet.
300
The unit used to measure the strength of a magnetic field is the: a. ohm. b. gauss. c. ampere. d. coulomb.
What is b. gauss.
300
Three ways you can increase the strength of an electromagnet are ____, ____ and add iron to the core. a. decrease the number of coils, increase the current b. increase the number of coils, increase the current c. increase the number of coils, decrease the current d. decrease the number of coils, decrease the current
What is b. increase the number of coils, increase the current
400
Which pair of objects in Figure 16-1A experiences an attractive force? a. A and B b. A and C c. B and D d. B and C
What is c. B and D
400
Dani and Gina are trying to make a permanent magnet out of an iron bar. Any of the following methods would permanently magnetize the iron bar EXCEPT: a. stroking the iron bar with a powerful magnet. b. placing the iron bar in a very strong magnetic field. c. placing the iron bar near a very strong electromagnet. d. placing the iron bar near a diamagnetic material.
What is d. placing the iron bar near a diamagnetic material.
400
Which of the following creates a magnetic field? a. A metal ball with 2 coulombs of static charge on it b. A piece of aluminum c. A coil of wire carrying current d. A diamagnetic material
What is c. A coil of wire carrying current
400
The difference between true geographic north and the “north” indicated by a compass is a difference measured in degrees and known as: a. inclination. b. declination. c. azimuth. d. elevation.
What is b. declination.
400
In Figure 16-2A, which direction should the magnetic field lines be pointing? a. From South to North b. From North to South c. From East to West d. From West to East
What is b. From North to South
500
The magnetic field strength inside a current-carrying coil will be larger if the coil is wound around a: a. vacuum. b. wooden rod. c. glass rod. d. iron rod.
What is d. iron rod.
500
All atoms act like tiny magnets. Why do only a few materials show magnetic properties? a. Magnetic materials have atoms that are much stronger magnets than the atoms of other materials. b. Atomic magnets are magnified when combined with a rare substance. Magnetic materials contain this rare substance. c. We see magnetic properties only if atomic magnets line up with Earth’s geographic south and north poles. In magnetic materials, this arrangement can occur. d. We see magnetic properties only if atomic magnets line up in the same direction throughout a material. In magnetic materials, this arrangement can occur.
What is d. We see magnetic properties only if atomic magnets line up in the same direction throughout a material. In magnetic materials, this arrangement can occur.
500
If a pin is brought close to a magnet, it is attracted to the magnet and attracts other pins to it. If the pin is removed from the magnet, it does not attract other pins.The pin might be referred to as: a. a hard magnet. b. a soft magnet. c. magnetic mono-pole. d. diamagnetic material.
What is b. a soft magnet.
500
According to historical data and current scientific theory, the statement that is NOT true concerning Earth’s magnetic field is that the field: a. reverses every 500,000 years. b. is weakening by 7% every 100 years. c. will reverse within the next 2,000 years. d. will completely disappear in the future.
What is d. will completely disappear in the future.
500
Explain why a magnet always attracts ferromagnetic materials even when they are not magnets.
What is the magnetic domains realign.
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